1. Field of the Invention
The present invention is concerned with a method of preparing novel compounds which are 1,2-dibromo-2-cyano-(substituted)alkanes. These novel antimicrobial compounds have a number of important industrial and agricultural applications.
As used herein, the term "antimicrobial" describes the killing of, as well as the inhibition of or control of the growth of bacteria, yeasts, fungi, and algae. A number of important industries can experience serious adverse effects from the activity of such bacteria and fungi on the raw materials which they employ, on various aspects of their manufacturing activities, or on the finished products which they produce. Such industries include the paint, wood, textile, cosmetic, leather, tobacco, fur, rope, paper, pulp, plastics, fuel, oil, rubber, and machine industries. Important applications include: inhibiting the growth of bacteria in aqueous paints, adhesives, latex emulsions, and joint cements; preserving wood; preserving cutting oils; controlling slime-producing bacteria and fungi in pulp and paper mills and cooling towers; as a spray or dip treatment for textiles and leather to prevent mold growth; as a component of anti-fouling paints to prevent adherence of fouling organisms, as a hard surface disinfectant to prevent growth of bacteria and fungi on walls, floors, etc.; and in swimming pools to prevent algae. The control of bacteria and fungi in pulp and paper mill water systems which contain aqueous dispersions of papermaking fibers is especially important. The uncontrolled buildup of slime produced by the accumulation of bacteria and fungi causes offgrade production, decreased production due to breaks and greater cleanup frequency, increased raw material usage, and increased maintenance costs. The problem of slime deposits has been aggravated by the widespread use of closed white water systems in the paper industry.
Antimicrobial compounds prepared by the method of the present invention are also utilized for agricultural applications, for example in preventing or minimizing the growth of harmful bacterial, yeast, and/or fungi on plants, trees, fruit, seeds, or soil.
2. Brief Description of the Prior Art
Lespieau et al. in Org. Syn. I. 209, describe preparation of 2,3-dibromopropene by dehydrobromination of 1,2,3-tribromopropane. Lespieau et al, in Org. Syn. I, 186 also describe coupling of a cyclohexyl group to 2,3-dibromopropene by means of cyclohexylmagnesium bromide.
Grignard, in Compt, Rend. 152:388-390 (1911), describes the reaction of a Grignard compound with cyanogen, but does not suggest that the Grignard compound can be unsaturated as in the method of the present invention.
Grignard et al., in Ann. de Chim. 4:28-57 (1915), describe in detail various reactions of Grignard compounds with cyanogen, but do not suggest that the Grignard compound can be unsaturated as in the method of the present invention.
Thus, none of the references discussed above, either singly or taken together, would suggest the novel method of preparation of the present invention.